There seem to be two kinds of horses: those that are eager to get into a trailer, and those that are eager to avoid getting in.

It seems to me that the difference between these kinds of horses comes down to education: those who want to get in have learned that the trailer ride is pleasant, and that what will happen at the destination is likely pleasant. Those who don’t want to get in have also been educated.

In the world of horses, everyone seems to confuse training and motivation, and thinks that if a horse won’t do something, it needs training. In fact, he often knows just exactly what to do, but needs motivation. We have too many horse trainers, and not enough horse motivators. Motivation matters.

Today I am lucky to have a mule who follows me into the trailer without need for a lead line (but I also rode five miles yesterday without touching the reins, so I guess she’s got me figured out.) In this column, I want to share some of the things I’ve learned about happy trailering.


  • Make sure your trailer is road-worthy. Brakes, tires (including spare), and wheel bearings should be inspected yearly. Tire inflation and the operation of running lights should be inspected before each trip. Grease the ball of the hitch, and be sure to use safety chains.
  • Add interior lighting. The eye of the horse does not adapt to sudden changes in lighting as quickly as a human’s eye.1 So entering a dark trailer or barn on a bright day can be scary. Leaving a well-lit arena at night can be scary. Running a steeplechase where the ground alternates between shade and full sun can be scary. Entering and leaving a well-lit check point in a night endurance ride can be scary. And exiting a dark woods into a bright open field can be scary. It is a good idea to turn on your interior trailer lights before loading, and turn on the lights over the aisle of the barn before bringing the boys in. Turn on your stall lights before leading your horse out in the day. And keep in mind that a horse might not fully recover his night vision when leaving a bright place for half an hour or more.2 Horses are adapted to the pace of lighting change of sunrise and sunset, not electric lighting.
  • Silence your trailer. Horses have much better hearing than we do, and trailers are louder inside when moving down the road than when sitting parked. A noisy trailer will stress and fatigue a horse, even if it doesn’t lead to premature deafness. Ask a friend to ride in your trailer for 5 minutes while you go down the road, listening for noises. Identify the sources of all this noise, and do what you can to fix it. Typical problem include pop rivets that have come loose, letting side panels rattle, rattling chain on chest and butt bars, and jangling tack.
  • A study at Cornell University suggests that trailered horses have the most problems when the trailer begins to move or when it goes around a curve3. My driving has improved since I added a pair of cameras (Uniden Guardian UDR777HD Indoor/Outdoor Wireless Security Camera system) inside the trailer, with a monitor next to me in the cab of your truck. Now I can see what my gal is up to, how a pothole or sudden braking has affected her, whether she has gotten tangled in anything. The camera system gives me great comfort – if you’ve seen me drive, you’d know why – and has taught me more about my gal. I feel an extra load of love when I watch her on the monitor, looking out the window and munching on some hay.
  • Temperature management is important. I plan to add several interior fans connected to a house battery, and will run them – particularly on hot summer days. I keep all windows open, and the scoops on the roof up, to ensure that she gets to savor the aromas of the countryside and keep her cool.
  • I always have fresh hay in nets that hang from the inside of the trailer, so that my gal can snack as she looks out the window. My trailer trips are usually under two hours, and so she doesn’t need water. But on a longer trip, you should bring water from her farm (I have a 30 gallon corner mounted tank that I fill at the farm, and use to fill a pan at rest or gas stops. Driving down the road can drain a bucket pretty fast, even with no horse in the back, so waiting until you are stopped is best.)


Configuring the Trailer

There has been lots of discussion on which way a horse would prefer to face in a trailer, and there are advocates for all possible directions.

Theory: Your own braking is likely to be more forceful than your acceleration, and so horses might be expected to prefer to face the direction that helps most with stability when the trailer is braking – which would be facing rear. Facing the rear of the trailer allows the use of their strongest leg muscles to hold them in place when you brake, and to use their butt, rather than their face, if they need to.

Observation: I drove one young mule 700 miles in my trailer, with all the dividers removed so he was free to roam. When I got home, he was standing on a diagonal, his butt lodged in a corner of the rear wall. I think that positioning helped him keep his balance while he slept. I drove my current mule 1000 miles under the same conditions, watching her with interior cameras. She spent nearly all her time sideways, looking out the window and eating hay.

Research: Some research addresses the question of which way a horse might prefer to face. In 1993, three American researchers drove horses over a standard course, alternating them between facing forward and facing backward. A researcher riding in the trailer with them recorded how often the horses impacted the sides or lost their balance. The study found that horses facing the rear had fewer side impacts, fewer total impacts, and fewer losses of balance.4 And what do horses prefer? In a study of horses transported loose in a stock trailer, horses spent significantly more time facing backward when the trailer was moving, but not when it was parked.5 6

While we are imagining the ideal configuration for the inside of a trailer, we should also wonder whether restraint is important. There are some who argue that tying a horse increases his or your safety, but others who argue that this can only lead to complications if the horse steps in the rope. There are some who argue that providing a horse with a narrow stall helps the horse maintain his balance, but others who observe that horses rarely lose their balance when they have room to roam in a stock trailer. The sides of a narrow stall would help us keep our balance, for sure. But compared to a horse, we are mighty unsteady on our feet. Studies have shown that horses spread their legs when in a trailer, to improve their stability.

If you have just one horse to put in your two-horse trailer, which side should it go in? Some have recommended the side closest to the crown of the road, to reduce the chance that a stumbling horse will flip the trailer. Others find that road vibration is worse on the side closest to the shoulder of the road.7 So both vibration and stability concerns argue for a “middle of the road” approach.

If you already own a trailer, your decision on which way your horse will face has likely already been made. And if you are nervous about what might happen with an unrestrained horse in a trailer, then continue with your restraints.

Since I only have one steed, and always ride alone, I tried taking out the chest bars, divider, and butt bars in my two-horse straight-load double axle gooseneck trailer to give my mule the most room to roam. Initially, I did this when I bought her, before starting the 1,000 mile non-stop trip home. But watching her with my camera system proved that this was the perfect one-horse setup. She never gave a hint of toppling when I did my craziest driving, no matter which way she was facing. She gave every hint of choosing which side she looked out of, and shifted her dining between hay nets and bucket of grain. I think this freedom is much of the reason she looks forward to getting into the trailer. With this freedom, she has told me how she likes to face: forward, on the diagonal, sideways, and backward. Her only preference seems to be standing near hay and grain, looking out a window. Freckles may or may not speak for all mules everywhere, and likely doesn’t speak for all horses.


If your horse is a reluctant loader, you won’t want to wait until loading day to work on this. In this preparation, our goal is not to get a horse on a trailer, but to get a horse more willing to get on a trailer. If actual loading happens in your first few sessions, great!

There are a few of my secrets to getting your horse to want to load:

  • Adjust your expectations. Maybe you think it is no big deal to walk up to a scary trailer. Go at your horse’s pace. Her eagerness to approach or avoid the trailer is her best statement about how she feels about it.
  • Patience will pay off. While you are being patient, your horse is becoming more familiar with the sight of the trailer and relaxing. But you and I are not famous for our patience. We need more patience, and more than that. The patience that you will need is not five or ten minutes. It is whatever it takes. If you need to stand near the trailer with your horse for an hour before she relaxes, then that’s what you need to do.
  • Open the side doors and turn on the interior lights, to minimize the brightness difference between inside and out.
  • Put a lead line on your horse, and walk her – at her pace – toward the truck and trailer. Walk around the rig many times, talking to her calmly, never bullying, always going at her pace, keeping that lead line slack. If she wants to graze while you are doing your laps, let her. Never put any tension on the lead line during this exercise. This familiarization should help get her heart rate down.
  • Let her look in the open side doors, and let her spend some time behind the ramp, taking in the sights and grazing. The more she looks into that trailer, the less threatening it will be.
  • Reward successive approximations. If she takes a step closer to the trailer ramp, reward. If she touches the ramp with a foot, reward. If she puts two feet on the ramp, reward. When she finally steps in, reward. Let her exit, and reward when she does. Repeat as time permits. [Reward need not be food or clicker. Your voice and chest scratches may work just as well for encouragement.]
  • Never pull on the lead line during this process. Do not use any “assistant” for the practice loadings: they won’t share your patience. We want your horse to believe he [note that Mr. Horse keeps changing sex in this article. You fix.] boarded of his own free will. And you want to get him to board all by yourself.
  • If you move ahead of your horse onto the trailer, don’t make eye contact with him, or even turn to face him. Do not use a crop or lunge whip, because they’ll be swinging around in the air in ways that you don’t intend them, and raising arousal level. You don’t want to add any unintended threat to this procedure.


Horses are designed differently than we are. They take in familiar sounds with their right ear, and novel sounds with the left. Visually, they take in a near-360 degree panorama, and seem to be able to see everything at once. Their sense of smell is thousands of times better than your dog’s. They are the multi-taskers. In comparison, my feeble CPU can only focus on one thing – or less – at once. So my idea of loading onto a trailer is walking forward and climbing on. Your horse, on the other hand, may need to check out a little grass, look over at the pasture, wonder what this funny thing is, and more. So there will be legitimate meanders and pauses in the best behaved horse. Forgive them for being horses, and indulge them a little as they try to please.

When my mule Freckles approaches the ramp, she is likely to follow to the last second, then swerve off to the side of the trailer, as if she has a bit of unfinished business: getting a last look, or saying good bye. I indulge her – she’s a mule, after all. But after a few seconds, I lead her back to the ramp, start up it, and use a hand signal to point toward the inside trailer corner where I temporarily tie her. If she doesn’t take a step forward, I may move part way toward her rump and extend an arm – never making contact with her. She understands this signal to mean move forward, and she walks calmly up the ramp and toward the front of the trailer. From the time she has gotten within 10 feet of the ramp, loading never takes more than a minute more. I will call this imperfect behavior perfect, and she makes me happy.

With Freckles, who is unrestrained while we drive down the road, I must still address the problem of her unloading herself at an inopportune time. So our ritual is always the same: I walk her on with halter and lead rope, and direct her to a front corner, where I connect a tie that is already tied to the inside of the trailer. I then drop her original lead rope in a corner on the floor. Now that she is restrained, I can exit and close up the back, enter from a side door, and unhook the tie. She is now unrestrained. During the trip, I watch her on my monitor. At our destination, I reverse the procedure, entering from a side door, connecting her to the tie, then opening the back, reconnecting her lead rope, unhooking the tie, and taking her to the outside of the trailer, where I tie her for tacking. It’s easier than it sounds.

At your destination

Every trailer loading means a trip to the unknown, and – for a race horse – maybe starting all over in building relationships. My mule, though, has learned that half of her loadings are the start of an adventure, and the other half the start of a happy trip back to the ranch.

Work to ensure that the adventures at your destination are as pleasant for your horse as they are for you. Make sure he gets food and the same tasty water from home that he’s used to. Make sure he doesn’t have to stand abandoned in the sun. If there is horse poop, let him smell it. If there are other horses, let them meet. If there is grass, it must be for him. Remember: he’s doing you a favor, and no matter how great the adventure, would likely rather be back at the ranch, hanging with his friends. Also remember: never squat while wearing spurs.

Happy Trails

If I needed to take two or more horses, and was going to start over, I would get a stock trailer. It is clear from watching Freckles with my camera and monitor that she enjoys the passing sights and smells. With a stock trailer, two horses can figure out how to stand without getting in each other’s faces. And I’d get another gooseneck – they are so much easier to turn in tight spaces, and provide a cozy place for you to spend the night when you and your girl go camping.

Long Term: don’t practice loading until you get it right. Practice until you can’t get it wrong. The best way to do this is to use that trailer every day, and have a new adventure every day. You can track my adventures with Freckles at


Sidebar: A Danish Study of Trailer Loading

In America, many horse trainers  have taught horses that not getting on a trailer can be more unpleasant than getting on. Researchers have noted that these common strategies of negative reinforcement can accidentally produce rearing or bolting, can increase the probability of undersirable behavior, can lead to habituation to the aversive stimulus, can strain the relationship between rider and horse, etc.8

But after all, loading is not about training at all. A reluctant horse knows how to board a trailer. It simply does not want to. The problem is motivation. Horses don’t likely enjoy being hit with a whip or crop, poked in the butt with a broom, or being tugged with a lead rope. Heart rates rise, and brute force regularly fails for any horse initially reluctant to enter a trailer. Even if it works, it isn’t going to leave your horse happy.

That doesn’t mean that clickers and treats are the solution. Some have pointed out that any learning situation can be tense, and any failure disturbing regardless of whether failure means punishment or simply no treat.

A study in Denmark9 compared traditional negative reinforcement (pulling on a lead rope, tapping with a dressage whip) with positive reinforcement (using clicker training and target training first, then using the target to lead the horse on, clicking and giving a food reward for good performance.) None of the horses in the study could be loaded into trailers by their owner at the start of the study. Horses were assigned to one of two groups, and both groups were first trained in one of these methods, and tested by using the methods to get them to walk across a tarp. Horse heart rates and behavior were carefully monitored and recorded throughout the trials.

Training was completed when the horse could enter the trailer upon a signal, or was terminated after a maximum of 15 sessions. Of the 12 horses, 10 reached the criterion within the 15 sessions. The findings certainly make the case for the value of positive reinforcement, clicker training, and target training:

  1. Horses trained with positive reinforcement spent less time per session to complete the training criterion. Positive reinforcement got the job done in 80% of the time that it took for a horse to load with negative reinforcement.
  2. Horses trained with positive reinforcement displayed significantly less discomfort behavior (widening of the eyes, widening of the nostrils, tail whipping and avoidance) per training session than horses trained with negative reinforcement. Positive reinforcement produced only 25% of the discomfort and 30% of the avoidance measured in the negative reinforcement condition.

This Danish study shows that for getting a horse to load, positive reinforcement might get a horse to load faster, with less discomfort, than negative reinforcement. Of course, the details matter, and a trainer who is good with one technique will likely do better using that technique than using another.

It might be that stress is a factor in learning: negative reinforcement adds stress, and when the situation is already stressful, it may be less effective than positive reinforcement; when we are just learning tricks, it may be more effective.

My encouragement for you is that you try to make trailer loading and trailering happy experiences for both of you. Strive for experiences that are so positive that you both want to do it again. Whether your involve carrots or chest scratches and sweet talk in this project is your business.

Sidebar: Associative Learning

Riding in a trailer might be not be as enjoyable for your horse as you imagine. Anything that works to take the fun out of a ride will also work to make loading a bigger problem.

We can use heart rate to assess excitement, arousal, and stress. During loading, heart rates climb.12 An elevated rate might signal nothing more than a horse’s arousal from all of the new sights, sounds, and smells it is taking in. Or it might reflect discomfort or distress from any number of sources:

  • Your trailer might be too hot – something you won’t know if you are sitting in the truck with the air conditioining running. One study, at least, has raised concerns about heat build-up in a four-horse slant load trailer.13
  • Poor air quality can also add to stress. The recent deaths of 16 ponies below deck in a ferry may have been due to carbon monoxide poisoning from vehicle engines, the same problem that two dogs experienced on this ship a few years back.14
  • Fatigue, high temperature, and dehydration can also raise the heart rate and presumably add to stress.

Perhaps reflecting the higher stress levels that come from riding in a trailer, studies have shown that horses eat and drink less while being transported.15

If your horse is stressed back there, his welfare suffers. And your next attempts to load may be more difficult.

Old Sidebar for another Day: Associative Learning

For ten years, I owned a wonderful horse, a thoroughbred, and from a line of horses that include War Admiral, Secretariat, Northern Dancer, Storm Cat, and Linkit. From his pastures in Kentucky when he was a baby to the end of his career at the track, he surely rode in a trailer many times. And so it is safe to assume that he knew how to climb into a trailer.

His life at the track was surely made worse by trailers. Every time he had to get in one, it must have meant he would be leaving his stable mates for parts unknown, perhaps never to see or smell or hear them again. So he knew how to get on and off a trailer. And I can’t imagine he looked forward to it.

When I adopted him, I paid someone with a stock trailer to take him to his new home. They arrived with a stock trailer, and we opened the back door. Carlos was ready to exert some serious force to make my horse get into the trailer, but I asked if I could give it a try. I walked into the trailer, and my horse followed at my heels. No problem. My horse was knowledgeable about a trailer, and he seemed to have a good attitude. I guess his experience at the track had not completely soured him on trailers.

When we got to our destination, I got in with my horse, and asked him to climb out. During the next 5 seconds, Carlos decided that my horse wasn’t coming off fast enough, entered the trailer and punched my horse in the face. My horse, in self-defense, jerked his head up, banging his head on the ceiling and opening a wound.

A few years went by before my horse needed another trailer ride. When he was given the opportunity to climb in — and Carlos was nowhere around — my horse would have none of it. My horse was still knowledgeable about a trailer and knew how to load, but now he had a bad attitude. If you think about it, Carlos taught my horse something. He taught him that the inside of a trailer was a dangerous place, where you could suddenly become very injured. My horse knew how to get into a trailer, how to balance during a long ride, how to get out. And he knew that something very bad could happen to you.

Some years later, I bought a truck and trailer so that I could have some distant adventures with my horse. In his first weeks with the trailer, he didn’t want to load. Many people would come by and suggest what should be done to train him, to induce him to get on. It took me some time to realize these truths: he was trained. He knew what I wanted. He wasn’t being a brat, he just didn’t want to do what all these helpful ladies wanted him to do. I think he dreaded getting on the trailer because he vaguely remembered the time Carlos mistreated him. His problem was not training in how to load. It was the training Carlos had given him, which taught him that being in a trailer is dangerous. Horses have good memories, and what my horse remembered from his most recent training was not good.

Eventually I discovered that the best place to try to load my horse was out of sight of the helpful impatient riders who knew so much more than me. His transition was quick. For our first five adventures with that trailer, he was slow to load at both farm and destination, but that loading time dropped rapidly. On our sixth field trip, he scrambled to get on the trailer when I put the ramp down, and scrambled when it was time to go home. I am sure that he scrambled because he knew it would be fun. All of his associations with the trailer were now positive.

If you are having issues with your horse, consider whether the problem is with his failure to understand what you want, or his lack of desire to do it. If your horse once loaded fine, but now doesn’t want to load, blame his history and associations with the task, not him. Blame punishment. Blame Carlos.

The interaction with my horse and Carlos was a case of associative learning. My horse learned an association between two stimuli: being in the trailer, and being punched in the face and smashed on the top of the head. Now, after some happy trips to happy times and back, my horse has replaced that association with another association: being in the trailer and getting hay, water, and a chance to see and smell the country going by.


1 Williams, Moyra. Horse psychology. Barnes, 1969.; Wouters, L., A. Moor, and Y. Moens. “Rod and cone components in the electroretinogram of the horse.” Zentralblatt für Veterinärmedizin Reihe A27.4 (1980): 330-338.

2 Wouters, L., A. Moor, and Y. Moens. “Rod and cone components in the electroretinogram of the horse.” Zentralblatt für Veterinärmedizin Reihe A 27, no. 4 (1980): 330-338.

3Lee, Joyce, Katherine Houpt, and Orla Doherty. “A survey of trailering problems in horses.” Journal of Equine Veterinary Science 21.5 (2001): 235-238.

4Clark, Diana K., Ted H. Friend, and Gisela Dellmeier. “The effect of orientation during trailer transport on heart rate, cortisol and balance in horses.” Applied Animal Behaviour Science 38.3-4 (1993): 179-189.

5Smith, B. L., Jones, J. H., Carlson, G. P., & Pascoe, J. R. (1994). Body position and direction preferences in horses during road transport. Equine veterinary journal26(5), 374-377.

6If your horse gets car sick when reading, he might prefer to face forward.

7Smith, B. L., Miles, J. A., Jones, J. H., & Willits, N. H. (1996). Influence of suspension, tires, and shock absorbers on vibration in a two-horse trailer. Transactions of the ASAE39(3), 1083-1092.

8Slater, Charlotte, and Simon Dymond. “Using differential reinforcement to improve equine welfare: shaping appropriate truck loading and feet handling.” Behavioural processes 86.3 (2011): 329-339.

9 Hendriksen, P., Elmgreen, K., Ladewig, J., 2011. Trailer-loading of horses: is there a difference between positive and negative reinforcement concerning effectiveness and stress-related signs? J. Vet. Behav. 6, 261–266.

10 Roberts, Monty. “Monty Roberts Horse Trailer Loading”

11 See Blackshaw, J.K., Kirk, D., Creiger, S.E., 1983. A different approach to horse handling, based on the Jeffrey method. Int. J. Study Anim. Probl. 4, 117-123.

12Shanahan, Stephanie. “Trailer loading stress in horses: behavioral and physiological effects of nonaversive training (TTEAM).” Journal of Applied Animal Welfare Science 6.4 (2003): 263-274.

13Purswell, J. L., Gates, R. S., Lawrence, L. M., & Davis, J. D. (2010). Thermal environment in a four-horse slant-load trailer. Transactions of the ASABE53(6), 1885-1894.

14Humphries, Alexandra. “Sixteen ponies die in transit from Tasmanian polo match.”

15Smith, B. L., Jones, J. H., Hornof, W. J., Miles, J. A., Longworth, K. E., & Willits, N. H. (1996). Effects of road transport on indices of stress in horses. Equine veterinary journal28(6), 446-454.